Manufacture of shoes having stiffened parts



s. P.- LOVELL MANUFACTURE OF SHOES. HAVING STIFFENED PARTS 2Sheets-Sheet 1 Filed Dec. 5, 1932 (aw/Z y s. P. LOVELL 2,@01,32

MANUFACTURE OF SHOES HAVING STIFFENED PARTS Filed Dec. 5, 1932 2Sheets-Sheet 2 dwpkr iatented May 14, 1935 PATENT OFFICE MANUFACTURE OFSHOES HAVING STIFFENED PARTS Stanley P. Lovell, Newton, Mass., assignorto Arden Box Toe Company, Watertown,

Mass., a

corporation of Massachusetts Application December 5 1932, Serial No.645,649

'1 Claims.

This invention relates to the manufacture of shoes having stiffenedparts, for instance, a stiffened fore part and/or a stifiened back orrear part.- p

5 In making shoes having stiffened parts, it has heretofore been thepractice to introduce under the upper leather of the shoe a stiffenerblank which prior to the lasting operation was made limp and moldable bysuitable treatment so as 10 to be conformable to the shape of the last.Such a blank was pre formed or pre-cut to'the desired shape and wasskived accurately at its marginal portionsto render the inside of theshoe smooth and comfortable as well as to avoid unsightly ridges on thesurface of the finished shoe. The stiifener blank usually consists of anintegral fibrous sheet serving as a carrier for a stiffening agent of acolloidal nature. It is common practice to impregnate a fibrous sheetwith such stiffening agent, to cut the stiffener blank from theimpregnated sheet, and finally to skive the blank at its marginalportions to a feather edge. The blank inthis form reaches the shoeoperator who renders it limp and moldable by the application of moderateheat .or by solvent action, depending upon the nature ofthe stiffeningagent. The operator then assembles the moldable blank with the shoeupper and performs the lasting and pulling-over operations which impartto the blank its desired permanent shape.

In accordance with l the present invention, rather than depending uponthe introduction of a, pre-formed stiflener blank into the shoe upper,

V the desired stifiening effect is realized by charging with stifi'eningagent at the desired zones the ,woven or other fabric which invariablyis associated with the shoe upper as a doubler and/or lining. Inaccomplishing this result, I first treat,

the desired zone or locality of the doubler and/or lining with a solventor gelatinizing liquid for the particular stiffening agent to beemployedand then associate with the liquid-treated'zone the stiffening agentunder conditions resulting in a substantially complete solution orfusion of the agent, in consequence of which 'the agent flows into thetreated zone, and, upon the evaporation of the solvent or gelatinizingliquid, functions to stiil'en such zone. Before such stiffening 'actionhas ensued, however, the liquid-treated zone toso gether with itsassociated dissolved or fused stifiening agent is. conformed to theshape of the last in the course of the usual shoe-making wo'perations.Byslmh practice, I may, for exam- 3 pie, eflect a 'stifi'ening of thetoe porton of ,the

:55 shoe, the stiffening agent existing in the doubler and/or lininginvariably forming part of the shoe upper assembly.

There are various ways of applying the principles of my invention. Letus assume, for example, that a shoe upper assembly is on the last 5 andis ready to be stiffened at its toe portion prior to conformation to thelast. In accordance with my invention, the toe portion of the doublerand/or lining of the upper assembly is treated by immersion, spraying,or other suitable treatment with a suitable solvent or gelatinizingliquid for the stiffening agent, the fabric constituting the doublerand/or lining thereby becoming charged with solvent or'gelatinizingliquid. A film of the proper stiffening material is now laid on the wetdoubler and/or lining and the upper assembly is then put through thepulling-over and bed-lasting operations. There are various combinationsof solvent or gelatinizing liquid and films of stiffening material whichmight be used in the practice of my invention. For instance, thedoubler-and/or lining can be treated with acetone, and films ofcellulose acetate or cellulose nitrate may be used as the stiffeningmedia. If desired, a film of gelatin may be used as the stiffeningmedium in which case, the doubler and/or lining may be treated withwater or dilute acetic acid as the solvent or gelatinizing liquid. Byusing a solvent or gelatinizing liquid of the proper kind and byassociating therewith a comparatively thin film of the stiffeningmedium, it is possible to sever the excess film lying outside of thesolvent-affected film area before or after the pulling-over andbed-lasting operations have been completed. Indeed, a properly wetdoubler and/or lining may be laid on a film or between two films ofstifiening medium, the other parts of the shoe assembly brought togetherover the film, and a film blank corresponding to the wet zone of thedoubler and/ or lining removed from the rest of the film. In otherwords, the solvent or gelatinizing liquid will etch or cut away from asheet of film material, as if by knife or die action, the desired areaof film material, for instance, an area corresponding to the toe portionof the upper. Rather than using a film for furnishing the stiffeningmedium to the wet doubler and/or lining, it is possible to apply solidpowdered stiifening medium thereto. For instance, the wet area of thedoubler and/or lining may be brought into contact with a mass of suchpowder or the powder may be sifted or projected 0 such area from aspraygun or atomizer. In su h case, however, there may be diiiiculty inrealizing a uniform stifiening effects The use With the forsgonig end;other features and objects in view, my invention will now be describedin conjunction with the accompanying drawings, wherein,

Figure l represcmts in plan view, before the operation, as shoe upperassembly, the portion oi the upper bemg lifted sway from the doubler andlining to show the solvent-treatd. Giza I Figure 2 is a, similar viewwith a film placed over the solvent-=treotod arcs.

Figine 3 illustmtes diagrammatically theblo'wing oi powderedstififening' medium over the solvent treotsd toe portion.

Figure 4 shows in perspective tho bottom of tho toe portion altos thepulling-over operation has ,,n completed, with the excess film beingreincv 'ei at the margins of the shoe upper.-

' or gcletinlzod and tends to diffuse into assembly. v I fabricconstitute ports of the shoe upper assembly and, after having suppliedwith the stifiemng medium in the up 1 and powdered iorrn respectively.

not previously been done.

Figures 5 and 6 are enlarged sectiom throu the stifiened ports of a shoeand illustrate the end results in the case of stiffening agent used mmFigure '7 is s side view of s shoe stifien'ed at its fore part inaccordance with my invention, the fore part being shown in section.

While the drawings illustrate the stifiening of the fore port of a shoein eccordance with my invention, it is of course possible to stiffenother ports, for instance, the buck or rear pert,und thus dispense withthe use of a so-callcd counter. As shown in Figure l, the toe portion Iof the doubler and/oz? lining of the shoeupper asseznbly may bethoroughly wet with a. solvent-.01 gelatinizing liquid, e. g., acetone,

medium. A film 2 of the stiffening medium may be laid upon thesolvent-treated area. Should there be excess film materiel outlying thesoivcnt trestcei treat, as shown in Figure 2, this excess may be readilyremoved. by bringing the upper 3; and the other parts of the upperassembly together, for! as hcreinbeiore observed, thev solvent sooncreates a the boundary of the solvent treated area. the upper" hasundergone tion has been conformed. to the shape of the last, asillustrated in Figm'c-i, it is also possible to remove readily theexcess film material 4 beyond the marginal portion of the upper, if thishas The excess film m'aterisl may be recovered and. reused in making newfilm moterial. Rather than using the stifiening agent in film form,powdered stiffening agent may, as illustrated in Flgu're'v3, be blown orotherwise projected on the solvent-treated area of the doubler and/orlining ofthe upper assembly. In any cvont, the solvent; ted oresreceives stlflcnlng medium. in such "form that the medium is,substantially completely dissolved the fabric of the doubler and/orlining of the shoegupper that a. doubler and lining line of cut orseverance at When been wet with solvent" ud.

propriate 10min ssscmbly is lasted and the solvent is permitted-toevaporatc,-the end result will be that illustrated lnFigures 5 and 6.Thus, as illustrated in both these figures, the stiifening medium willdiffuse into the fabric layers and this nation's; be promoted by thepressure ap- I y when cellulose acetaste or cellulose nitraw is to serveas the stiffening v lasting and its toe por- 'selves advantageously toplied in shaping the ,upperussembly to the last. Such stiffening mediumas remains as a. coating on the lining and doubler serves to-cement orbond together the successive the shoe upper, increasing the strength ofthe shoe upper structure at its stifiened portion. The stiffened portionis not appreciably thicker than the unstiffened therefore assumes thelines of the last more faithfully than is the case when. a. stiffenerblank; of substantial thickness forms part of the shoe upper assembly usin prior art practice. Thus, as shown in'Figure '7, the stiffened toeportion 5 of the shoe is not visibly thicker than the unstifiened vampportion and, accordingly, there is no tendency for '9. ridge to beraised in the shoe upper at the vamp line.

There are many advantages inherent in the practice of stiffening shoeparts in accordance with my invention. My invention makes possible thedesired stiifening effect without the introductlon into the shoeupperoba blank which is apt to work loose in the shoe under the stressesof use. Moreover, the practice of my invention means that the expenseincident to using additional fabric in making shoe stifiener blanks andin cutting, skiving, sorting and packing preformed blanks is, done awaywith. Shoe parts stiffened in accordance with my invention are capableof withstanding the stresses of use for the life of the for thestiffening medium is integral with, or part of, the shoe upper assembly.

In using films of stiffening medium in accordance with my invention, thethickness of the film may be coordinated with the degree of stiffnessdesired in the finished shoe. For instance, a womans dancing shoe needrequire a, film of, say, cellulose acetate of only about .003 inchthickness, whereas a woman's street shoe may require two such films nextto the doubler. On the other hand, a man's dress shoe may-require theuse of cellulose thickness sad 2. men's street or work shoe may requiretwo such films next to the doubler. In any one of these cases, however,the film required is so thin that it is promptly dissolved orgelatinized substantially completely when brought in contact with a,doubler sud/or lining wet with the appropriate solvent.

While I have .herelnbelore described various preferred stilfening media,which lend themvin film form, for the purposes stiflening agents. Thus,practiced in connection with a. ing agent, it is possible to use a widevariety of stiffening agents, including not onlytbose hereinbcforementioned, but such other agents as resins, bitumen, which are solublein various organic solvents, as

nevertheless, it is possible to use of my invention various other whenmy invention is well as water-soluble agents like caseimdextrm On theother hand,

gum arabimorthe like. when the stiffening agent is used in film form,such other film-forming stiffening pgents no caseim'slbumen, (e. g.,blood albumen), gums,

layers constituting portions of the shoe and acetate film of .00! inch'formation and handling powdered stiffenhard waxes,.or tbelrequivolents,

(e. g., gum shellac), and artificial resins of the vinyl and rosyresins, might be employed. A caseincr albumen film may be acted upon bysuitable alkaline aqueous solvent media, e. g., water, whereas gums-orartificial resins like we, fvinyl" and "rezylf' resins are soluble invarious organic so! vents, such as the hydrocarbons. ,flcohols, others,or mixed solvents of this typo.

class of the so-colled layer of fabric, those steps which comprisewetting said fabric with 'a solvent for stiflening agent at the desiredzone, associating solid stiffening agent with said wet zone in a formconduclve to a prompt and substantially complete solution of saidstiifening agent, and conforming said zone to the shape of the last.

2. In a method of shoemaking which involves I lasting a shoe upperassembly having an internal layer of fabric, those steps which comprisewetting said fabric with a solvent for stiffening agent at the desiredzone, associating stiflening agent with said wet zone in thin film formconducive to a prompt and substantially complete solution of said film,and conforming said zoneto the shape of the last.

3. In a method of shoemaking which involves lasting a shoe upperassembly having an internal layer' of fabric, those steps which compisewetting said fabric with a solvent for stiffening agent at the desiredzone, associating stifl'ening agent with said wet zone in a powderedform conducive to a prompt'and substantially complete solution oLsaidstiffening agent,- and conforming said zone to the shape of the last.

. 4,111 a method of shoemaking which involves lasti ng a shoe upperassembly having an internal layer of fabric, those steps which comprisewetting the i'ore part of said fabric with a solvent for cellulose esterstiilening material, applying cellulose ester to said wet fore part inthin fllm form conducive to a prompt andsubstantially '3 completesolution of said firm, and conforming said fore part to the shape of thelast.

5. In a method of shoemaking which involves lasting a shoe upper,assembly having an internal layer of fabric, those steps which comprisewetting tbefore part of said fabric with a solvent for cellulose esterstiflening material. applying cellulose ester to a face of said wetforepart in thin iilm form conducive to a prompt and substantiallycomplete solution of said film, removing any fllm outlying said wet forepart after the solvent has acted upon the film in contact therewith andhas madesaid, outlying film easily removable, and conforming the forepart to the shape of the last.

6. In a method of 'shoemaking which involves lasting a shoe upperassembly having an internal layer of fabric, those steps which comprisewetting the fore part of said fabric with a volatile. nitrocellulosesolvent, applying nitrocellulose to said wet fore part in thin fllmformconducive to a prompt and substantially complete solution of lay: offabric, those steps which comprise wetting the fore part of saidfabricwith a volatile solvent for cellulose acetate, applying celluloseacetate to said wet fore part in thin film form conducive to a promptand substantially com-' plete solution of said fllm, and conforming saidfore part to the shape of the last.

STANLEY r. Lovma.

